Zero crossing contactor and method of operating

ABSTRACT

A contactor apparatus and method for operating the contactor apparatus can include a contactor assembly with a contactor coil operably coupled to a contactor switch. One or more sensors can be provided in the contactor assembly adapted to measure one or more aspects of the contactor assembly. Based upon the measured aspects, a controller can initiate operation of the contactor switch to effectively toggle the contactor switch at a zero-crossing point along an alternating current waveform.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.16/394,347, filed Apr. 25, 2019, now allowed, which claims priority toand the benefit of British Patent Application No. 1806782.7 filed Apr.25, 2018, both of which are incorporated in their entirety by reference.

BACKGROUND

In electrical power systems, there is often a need to electricallyswitch on and switch off the power system or portions thereof. Inalternating current (AC) systems, the current periodically reversesdirection, varying between a positive and negative voltage in asinusoidal cycle. At the change between directions, the voltage is zero.Traditional AC contactors will switch at any point during the AC cycle,without regard to the current or voltage. Switching a contactor in thismanner can lead to voltage or current spikes, voltage surges, contactwear at the contactor and other stresses, noise, arcing, and depositionfrom arcing.

BRIEF DESCRIPTION

In one aspect, the disclosure relates to a method of operating acontactor, the method comprising receiving, in a controller module, atleast two operational characteristics of the contactor, with eachoperational characteristic representative of a delay time, determining,in the controller module, a contactor time delay for at least one ofdisconnecting or connecting a power supply by the contactor, thecontactor time delay being a summation of a set of delay timings basedon the delay time of each operational characteristic, and initiating, bythe controller module, the at least one of disconnecting or connectingof the power supply by the contactor at an initiation time prior to azero-crossing voltage of an alternating current (AC) waveform of thepower supply, wherein the initiation time anticipates the zero-crossingvoltage based upon the contactor time delay.

In another aspect, the disclosure relates to a method of operating acontactor, the method comprising receiving, in a controller module, atleast two operational characteristics of the contactor, with eachoperational characteristic representative of a delay time, determining,in the controller module, a total contactor time delay defined by atiming estimation to operably disconnect or connect a power supply andan electrical load, based on the delay time of each operationalcharacteristic, determining a contactor initiation time based on atleast one delay time and an alternating current (AC) waveform of thepower supply, such that an expiration of the total contactor time delaycoincides with a zero-crossing voltage of the AC waveform, andinitiating, by the controller module, a toggling of the power supply bythe contactor at the contactor initiation time.

In another aspect, the disclosure relates to a method of operating acontactor, the method comprising receiving, in a contactor assemblycomprising a contactor switch selectably connecting an input with anoutput, a contactor coil operably coupled to the contactor switch andconfigured to actuate the contactor switch, at least two sensorsconfigured to measure an operational characteristic of the contactorassembly, and a controller module configured to receive at least twoelectrical signals from the at least two sensors, with each electricalsignal representative of a delay time, determine a contactor time delayas a summation of a set of delay timings based upon the at least twoelectrical signals, and initiate at least one of a disconnecting orconnecting of the input and the output by the contactor switch at aninitiation time prior to a zero-crossing voltage of an alternatingcurrent (AC) waveform of a power supply wherein the initiation time isbased upon the contactor time delay.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a top down schematic view of an aircraft and powerdistribution system in accordance with aspects described herein.

FIG. 2 is a schematic view of an electrical circuit forming a portion ofthe power distribution system of FIG. 1 including a contactor assembly,in accordance with aspects described herein.

FIG. 3 is a graph plotting an alternating current waveform for theelectrical circuit of FIG. 2, including a total delay prior to azero-crossing point, in accordance with aspects described herein.

FIG. 4 is a block diagram illustrating a method of operating thecontactor assembly of FIG. 2, in accordance with aspects describedherein.

DETAILED DESCRIPTION

The disclosure is related to a zero-crossing contactor assembly andmethod of operating, which can be used, for example, in a powerdistribution system for an aircraft. While this description is primarilydirected toward a power distribution system for an aircraft, it is alsoapplicable to any environment utilizing an alternating currentelectrical system, such as any power distribution system in non-aircraftimplementations.

As used herein, the term “upstream” refers to moving in a directiontoward an inlet or beginning position, or a component being relativelycloser to the inlet or beginning position as compared to anothercomponent. The term “downstream” refers to a direction toward an outletor end position or being relatively closer to the outlet or end positionas compared to another component. Furthermore, the terms “upstream” or“downstream” can be used as a reference relative to a current directionfor an alternating current circuit, which can reverse directionperiodically, defining the meaning of the terms “upstream” or“downstream” based upon the current direction for the circuit.Furthermore, as used herein, the term “set” or a “set” of elements canbe any number of elements, including only one.

All directional references (e.g., radial, axial, proximal, distal,upper, lower, upward, downward, left, right, lateral, front, back, top,bottom, above, below, vertical, horizontal, clockwise, counterclockwise,upstream, downstream, forward, aft, etc.) are only used foridentification purposes to aid the reader's understanding of the presentdisclosure, and do not create limitations, particularly as to theposition, orientation, or use of aspects of the disclosure describedherein. Connection references (e.g., attached, coupled, connected, andjoined) are to be construed broadly and can include intermediate membersbetween a collection of elements and relative movement between elementsunless otherwise indicated. As such, connection references do notnecessarily infer that two elements are directly connected and in fixedrelation to one another. The exemplary drawings are for purposes ofillustration only and the dimensions, positions, order and relativesizes reflected in the drawings attached hereto can vary.

Additionally, while terms such as “voltage”, “current”, and “power” canbe used herein, it will be evident to one skilled in the art that theseterms can be interchangeable when describing aspects of the electricalcircuit, or circuit operations.

Also as used herein, while sensors can be described as “sensing” or“measuring” a respective value, sensing or measuring can includedetermining a value indicative of or related to the respective value,rather than directly sensing or measuring the value itself. The sensedor measured values can further be provided to additional or separatecomponents. Such a provision can be provided as a signal, such as anelectrical signal, to said additional or separate components. Forinstance, the measured value can be provided to a controller module orprocessor, and the controller module or processor can perform processingon the value to determine a representative value or an electricalcharacteristic representative of said value.

As used herein, a “system” or a “controller module” can include at leastone processor and memory. Non-limiting examples of the memory caninclude Random Access Memory (RAM), Read-Only Memory (ROM), flashmemory, or one or more different types of portable electronic memory,such as discs, DVDs, CD-ROMs, etc., or any suitable combination of thesetypes of memory. The processor can be configured to run any suitableprograms or executable instructions designed to carry out variousmethods, functionality, processing tasks, calculations, or the like, toenable or achieve the technical operations or operations describedherein. The program can include a computer program product that caninclude machine-readable media for carrying or having machine-executableinstructions or data structures stored thereon. Such machine-readablemedia can be any available media, which can be accessed by a generalpurpose or special purpose computer or other machine with a processor.Generally, such a computer program can include routines, programs,objects, components, data structures, etc., that have the technicaleffect of performing particular tasks or implement particular abstractdata types.

As used herein, a controllable switching element, or a “switch” is anelectrical device that can be controllable to toggle between a firstmode of operation, wherein the switch is “closed” intending to transmitcurrent from a switch input to a switch output, and a second mode ofoperation, wherein the switch is “open” intending to prevent currentfrom transmitting between the switch input and switch output. Innon-limiting examples, connections or disconnections, such asconnections enabled or disabled by the controllable switching element,can be selectively configured to provide, enable, disable, or the like,an electrical connection between respective elements.

The disclosure can be implemented in any electrical circuit environmenthaving a switch, electrical switch, or switching element. A non-limitingexample of an electrical circuit environment that can include aspects ofthe disclosure can include an aircraft power system architecture, whichenables production of electrical power from at least one spool of aturbine engine, preferably a gas turbine engine, and delivers theelectrical power to a set of electrical loads. In one non-limitingexample, the electrical switch or switching element can include at leastone solid state switch, such as a solid state power controller (SSPC)switching device. One non-limiting example of the SSPC can include asilicon carbide (SiC) or Gallium Nitride (GaN) based, high power switch.SiC or GaN can be selected based on their solid state materialconstruction, their ability to handle high voltages and large powerlevels in smaller and lighter form factors, and their high speedswitching ability to perform electrical operations very quickly.Additional switching devices or additional silicon-based power switchescan be included.

As illustrated in FIG. 1, an aircraft 10 is shown having at least onegas turbine engine, shown as a left engine system 12 and a right enginesystem 14. Alternatively, the aircraft 10 can have fewer or additionalengine systems. The left and right engine systems 12, 14 can besubstantially identical, and can further include at least one electricmachine, such as a generator 18. The aircraft 10 is shown furtherincluding a plurality of power-consuming components, or electrical loads20, for instance, an actuator load, flight critical loads, andnon-flight critical loads. The electrical loads 20 are electricallycoupled with at least one of the generators 18 via a power distributionsystem 22.

In the aircraft 10, the operating left and right engine systems 12, 14generates mechanical energy which can be extracted via a spool, toprovide a driving force for the generator 18. The generator 18, in turn,delivers the power to the electrical loads 20 via the power distributionsystem 22 for load operations. Additional power sources for providingpower to the electrical loads 20, such as emergency power sources, ramair turbine systems, or starter/generators, are envisioned. It will beunderstood that while the power distribution system 22 is shown in anaircraft environment, the power distribution system is not so limitedand has general application to electrical power systems in non-aircraftapplications, such as other mobile applications and non-mobileindustrial, commercial, and residential applications.

Referring now to FIG. 2, an electrical circuit 30 can form at least aportion of the power distribution system 22 having the contactorassembly 32. It should be understood that the electric circuit 30 ismerely one example aspect of an electrical network or power distributionsystem 22, or subcomponents thereof, for ease of understanding. Furthernon-limiting examples of the disclosure can be included or contained asa portion of a printed circuit board, field programmable gate array(FPGA), or the like.

The contactor assembly 32 can form a portion of the circuit 30,positioned between a power supply input 34, such as the generator 18(not shown), and a power supply output 36 connected with a powerconsuming device, such as the electrical load 20 (not shown). Innon-limiting examples, the power supply input 34 can include a voltageinput and the power supply output 36 can include a voltage output. Thecontactor assembly 32 can further include a contactor 38 schematicallyshown to include a switch 40 and a contactor coil 42. The switch 40 canbe configured to move between a first opened condition or state and asecond closed condition or state. In the opened condition, the contactor38 or switch 40 prevents, disconnects, or otherwise disables currentconduction between the power supply input 34 and the power supply output36, while in the closed condition, the contactor 38 or switch 40permits, allows, connects, or otherwise enables current conductionbetween the power supply input 34 and the power supply output 36. Theswitch 40 can be operable between the first opened condition or thesecond closed condition by selective energization of the contactor coil42. For example, the application of a voltage or power to the coil caneffectively or operably close the switch, while the lack of a voltage orpower to the coil can effectively or operably open the switch. Onenon-limiting example for the contactor assembly 32 can include asolenoid, while any suitable element or component configured to actuateor be energized to actuate the switch 40 within the contactor 38 iscontemplated.

The circuit 30 can further include a coil switch 48 connected to thecontactor coil 42 at a first end 44 of the contactor coil 42. The coilswitch 48 can be operable between a first opened condition or state anda second closed condition or state, In the first opened condition, avoltage or power is prevented, disconnected, or otherwise disabledacross the coil switch 48, while in the second closed states, a power orvoltage is permitted, allowed, connected, or otherwise enabled acrossthe coil switch 48. In one non-limiting example, a contactor coilenergizing supply 50 can include a power supply or a power source thatelectrically and selectively couples to the coil switch 48, selectivelyproviding a voltage or power to the coil switch 48. The circuit 30 canfurther include a ground 52 provided at a second end 46 of the contactorcoil 42, opposite of the coil switch 48, electrically grounding thecontactor coil 42.

The contactor assembly 32 can further include a controller module 60electrically couple within the circuit 30. The controller module 60 caninclude at least one processor 64 and memory 66, and can be configuredto run any suitable program or executable instructions designed to carryout operation of the circuit 30, the contactor assembly 32, or portionsthereof. The controller module 60 can be controllably connected with thecoil switch 48, such that the controller module 60 can generate, send,or otherwise provide a control signal 54 (shown as a dotted arrow) toselectively control the switching between the first and second states ofthe coil switch 48.

A command controller 62 can be further communicably coupled with thecontroller module 60, and can be configured to provide a command, suchas an instruction to open or close a switch, or operate a portion of thecircuit 30. The command controller 62 can also include at least oneprocessor and memory (not shown), and can be configured to run anysuitable program or executable instruction. While shown adjacent thecontroller module 60, the command controller 62 can be located remotelyfrom the controller module 60, and adapted to send a signal orinstruction to the controller module 60 relating to the contactorassembly 32 or the circuit 30.

A set of sensors 70 can be included with the contactor assembly 32, andcan include a contactor coil operational characteristic sensor 72, awaveform sensor 74, and a temperature sensor 78. The set of sensors 70can be communicatively and operatively couple with the controller module60, such that the set of electrical signals can be generated, provided,supplied to, or otherwise received by the controller module 60. Thecontactor coil operational characteristic sensor 72 can be configured togenerate a signal representative of a voltage, current, or otherwise,which can be representative of an operational characteristic of thecontactor coil energizing supply 50. Non-limiting examples ofoperational characteristics can include an “on” characteristic or an“off” characteristic, for example, as well as an “active,” “inactive,”“closed,” or “opened” in additional non-limiting examples. Additionally,the set of sensors 70 is further shown including an optional outputvoltage sensor 76. While shown as four sensors, it is contemplated thatthe set of sensors 70 can include additional or fewer sensors. Thecontactor coil operational characteristic sensor 72 can couple to thecircuit 30 between the contactor coil energizing supply 50 and the coilswitch 48. In one non-limiting example, the waveform sensor 74 cancouple to the circuit 30 between the power supply input 34 and theswitch 40 and can be configured or adapted to sense or measure awaveform frequency for the AC current passing across the switch 40 fromthe power supply input 34 to the power supply output 36. The waveformsensor 74 can be configured to generate a signal representative of analternating current (AC) waveform supplied by the power supply input 34.Such a waveform can be substantially sinusoidal, represented as areversing current direction over a period of time. In anothernon-limiting example, the output voltage sensor 76 can couple thecircuit 30 between the switch 40 and the power supply output 36, and canbe configured or adapted to sense or measure a voltage downstream of theswitch 40, between the contactor assembly 32 and the power supply output36. The output voltage sensor 76 can be configured to generate a signalrepresentative of a voltage, such as a voltage transmitted by way of thecontactor assembly 32 when the switch 40 is in the second closedposition. The temperature sensor 78 can be positioned to measure atemperature of the contactor coil 42, and configured to generate asignal representative of a temperature of the contactor coil 42.

During operation, the contactor assembly 32 or contactor 38 operates toselectively enable or disable conduction of power supplied to the powersupply input 34 to the power supply output 36. The selective enabling ordisabling can be operably or effectively controlled by way of thecontroller module 60. In one non-limiting example, the commandcontroller 62, or another controlling component, can supply or provide ademand, desire, or instruction to the controller module 60 to connect ordisconnect the power supply input 34 from the power supply output 36 byway of the contactor coil 42, the coil switch 48, the control signal 54,and the contactor coil energizing supply 50, or a combination thereof.Such an instruction can be based on a schedule or can be on demand.Based upon said instruction, the controller module 60 operably oreffectively supplies the control signal 54 to the coil switch 48,instructing or controlling the coil switch 48 to toggle to the closedstate, energizing the contactor coil 42 with the contactor coilenergizing supply 50. Therefore, operation of the switch 40 of thecontactor 38 is controlled by way of selectively powering the contactorcoil 42 in response to the control signal 54 from the controller module60. Thus, the controller module 60 can effectively operate the contactorassembly 32.

Operation of the contactor assembly 32 can further be based on a numberof operation characteristics. For example, the operationalcharacteristics can include at least one of a frequency of the electriccurrent supplied to the power supply input 34, a coil temperature, acoil operational characteristic, an error correction, or a combinationthereof. The frequency of the electrical circuit can be representativeof a sinusoidal electrical frequency for the alternating electricalcurrent passing from the power supply input 34. In one non-limitingexample, the determination of the frequency of the electrical circuitfrom the power supply input 34 can include sensing the frequency, or acharacteristic of the frequency such as a zero-crossing voltage, withthe waveform sensor 74, and generating and providing a signalrepresentative of the waveform or waveform characteristic to thecontroller module 60.

The contactor coil temperature can be representative of a temperature ofthe contactor coil 42 both when the contactor coil 42 is energized andis not energized. In one non-limiting example, the determination of thecoil temperature can be determined by sensing the temperature of thecontactor coil 42 with the temperature sensor 78, and generating andproviding a signal representative of the temperature of the contactorcoil 42 to the controller module 60.

The coil operational characteristic can include an “on” or an “off”characteristic, such as the time it takes to open or close the coilswitch 48. Such a coil operational characteristic can be determined bysensing an electrical characteristic of the coil switch 48 or thecontactor coil energizing supply 50 by way of the contactor coiloperational characteristic sensor 72. A signal representative of thecoil operational characteristic can be generated and provided by thecontactor coil operational characteristic sensor 72 to the controllermodule 60.

An error correction can include a measurement indicative of orrepresentative of an error measurement of the circuit 30, that is, adifference in expected operation of the circuit 30, the contactor 38, orthe contactor assembly 32, compared with the actual operation of thecircuit 30, the contactor 38, or the contactor assembly 32.

The controller module 60 can store at least a subset of the signalsreceived from the set of sensors 70 in the memory 66. The controllermodule 60, receiving or storing the electrical signals from the set ofsensors 70, can utilize the processor 64 to incorporate the electricalsignals as values to initiate disconnecting or connecting of the powersupply from the power supply input 34 and the power supply output 36.While aspects of the disclosure are described with respect to“disconnecting” the power supply from the power supply input 34 from thepower supply output 36, it will be understood that the disclosure isalso applicable to any connecting, or any toggle or toggling of thecontactor between a disconnecting and connecting operation. Morespecifically, the controller module 60 can determine a disconnection,connection, or contactor time delay based upon the values of theelectrical signals from the set of sensors 70. For example, thetemperature value of the contactor coil 42 provided by the temperaturesensor 78 can be representative of a first time delay such as a coiltemperature delay time. As used herein the contactor coil 42 temperaturedelay time is representative of a delay in timing in the contactor coil42 operably effecting the switch 40 to toggle between opened and closedstates, due to the temperature of the contactor coil 42. For example,the temperature of the contactor coil 42 affects the operation of thecoil, wherein a higher temperature generally causes an increased delayin toggling the switch 40, whereas a lower temperature of the contactorcoil 42 generally causes a reduced delay in toggling the switch 40.

A contactor coil operational characteristic provided by the contactorcoil operational characteristic sensor 72 can be representative of asecond time delay such as a coil operational characteristic delay time,which is representative of the expected delay in sufficiently energizingthe contactor coil 42 by way of the contactor coil energizing supply 50and the coil switch 48. The contactor coil operational characteristiccan include, or be at least partially based on, the supply voltage ofthe contactor coil energizing supply 50, the time delay in operating thecoil switch 48 after receiving a control signal 54, or a combinationthereof. The time for providing a signal across the circuit 30 can berepresentative of a third time delay such as an electrical signal delaytime, based on the specific configuration of the circuit signal traces.An error correction value can be representative of a fourth time delaybased on a difference in expected operation of the circuit 30, thecontactor 38, or the contactor assembly 32, compared with the actualoperation of the circuit 30, the contactor 38, or the contactor assembly32. In one non-limiting example, the error correction characteristic caninclude sensing or measuring the voltage at the power supply output 36,by the output voltage sensor 76. In this example, the output voltagesensor 76 can generate and provide a signal representative of thevoltage, such as when the voltage increases, decreases, or the like, tothe controller module 60. In response, the controller module 60 cancompare an actual timing of the signal representative of the voltagefrom the output voltage sensor 76, and compare the timing with theexpected, estimated, calculated timing of the circuit 30 operations. Forinstance, if the controller module 60 initiates a “disconnect” or“connect” command to operably toggle the switch 40 of the contactor 38to disable or enable supplying power to the power supply output 36, thecontroller module 60 can receive a signal indicating when the voltage atthe power supply output 36 falls (e.g. when the power is disconnected orconnected), by way of the output voltage sensor 76. A difference incompared or expected timing can result in a determined error correctioncharacteristic. In one non-limiting example, it will be understood thata calculated, compared, or determined error correction characteristiccan be represented as an “error delay time,” and accounted for in thefollowing or a subsequent connection or disconnection cycle.

Referring to FIG. 3, a graph 90 includes a plot showing a sinusoidalalternating current (AC) waveform 92 representing an amplitude for analternating current passing along the circuit 30 over a period of time.In one non-limiting example, the AC waveform 92 can be representative ofa signal provided to the controller module 60 from the waveform sensor74. The AC waveform 92 includes a set of zero-crossing points 94,representative of a zero voltage or current as the alternating currentreverses direction. Such zero-crossing points 94 can be determined bythe controller module 60 based upon a consistent frequency for thecurrent, such that the controller module 60 can accurately predict aschedule for future zero-crossing points 94. It is beneficial to operatethe contactor assembly 32 such that the effective connecting,disconnecting, enabling, or disabling of the contactor assembly 32coincides with the zero-crossing point. However, as described above withrespect to the delays, the initial decision or initiation of operationof the contactor assembly 32 does not effectively or instantaneouslyresult in the opening or closing of the switch 40, as set of operationaldelays can be intervening. Thus, non-limiting aspects of the disclosurecan be included wherein the controller module 60 can determine a totalcontactor time delay, that is, an estimated, predicted, or otherwisedetermined summated time delay between initiating a disconnection orconnection command, instruction, or control signal, and the actual oreffective disconnection or connection of the power conducted via thecontactor 38, and initiate the disconnection or connection such that theeffective disconnection or connection coincides with the zero-crossingpoints 94. While the specific example of initiating a “disconnect” isdescribed, non-limiting aspects of the disclosure are also applicableand included wherein the controller module 60 can determine a totalcontactor time delay and initiate the connecting or supplying of thepower conducted via the contactor 38, and such that the effectiveconnecting coincides with the zero-crossing points 94.

A total delay time 80 can include the summation of a set of delaytimings, including but not limited to, the coil temperature delay time82, the coil operational characteristic delay time 84, the electricalsignal delay time 86, and the error delay time 88, as described above.As illustrated, the controller module 60 can determine a total timedelay 80 of the aforementioned delays, or determine individual delaysfor each respective delay, which can be summated in a subsequent step.Additionally, it is contemplated that the aforementioned delay times 82,84, 86, 88 and any other delay between initiating a disconnecting orconnecting of the power supply by the contactor 38 in anticipation of azero-crossing voltage of the AC waveform 92, and the effectivedisconnecting or connecting of the power supply, can be utilized indetermining a total delay time 80. While shown as four delays as 82, 84,86, 88, any number of intervening, determined, calculated, or comparisondelays is contemplated, as any system component or operational functioncontributing to total delay time 80, which results in a delay of timebetween initiating an instruction to open the switch 40 and effectivelydisconnecting or connecting the power supply input 34 and the powersupply output 36. Additionally, while the set of time delays areillustrated as approximately the same length of time (e.g. the same timedelay) the example delays are for purposes of illustration only and thetime delays for the collective set of time delays, or the relative delaytimings can vary.

The processor 64 in the controller module 60 can calculate the totaltime delay 80 based upon the signals received from the contactor coiloperational characteristic sensor 72, the output voltage sensor 76, andthe temperature sensor 78, or optionally including any other time delayor sensor input, and determine a schedule, estimation, prediction, orthe like, for a subsequent or upcoming zero-crossings for the ACwaveform 92 from the signal provided by the waveform sensor 74. Thecontroller module 60 can then calculate an initiation time 96. Theinitiation time 96 can be a time calculated as an anticipatedzero-crossing point 94 minus the total delay time 80. Still referring toFIG. 3, the initiation time 96 is determined prior to a zero-crossingpoint 94 by the total delay time 80 as the sum of the time delays 82,84, 86, 88.

The controller module 60 can initiate operation of the switch 40 at theinitiation time 96 to coincide with the zero-crossing point 94 of the ACwaveform 92 to effectively disconnect or connect the switch 40 at thezero-crossing point 94. In this manner, the contactor assembly 32 canutilize the set of sensors 70 and the controller module 60 toeffectively calculate an operational delay for the contactor assembly32, and can operate the switch 40 to coincide with the zero-crossingpoint 94 for the AC waveform.

Similarly, the controller module 60 can utilize the output voltagesensor 76 to continuously determine the error delay time 88 based upon avoltage between the switch 40 and the power supply output 36.‘Continuously’ as used herein can mean at an operation of the contactorassembly 32. Alternatively, the output voltage sensor 76 can make anon-demand measurement, such as when a predicted, calculated, determined,or estimated total delay time 80 is found to be outside an expectedrange or threshold of operation, such as a predetermined tolerance. Ifsuch a measured voltage is not zero, the delay for the error delay time88 can be updated after operation of the contactor assembly 32, andinput into the controller module 60 to update the total delay time 80for future operations of the contactor assembly 32. Therefore, as thecontactor assembly 32 changes over time, such as degradation due to ageor other environmental factors, the output voltage sensor 76 can providefor updating the error delay time 88. As such, an accurate zero-crossingswitch can be consistently achieved, particularly over time.

Referring now to FIG. 4, a flow chart demonstrates a method 100 ofoperating a contactor 32 can include receiving, in a controller module60, an electrical signal representative of an alternating current (AC)waveform 92 of a power supply or power supply input 34, at 102. Themethod 100 can further include receiving, in the controller module 60, atemperature value representative of a temperature of a contactor coil42, at 104. Alternatively, the method 100 could include receiving, inthe controller module 60, the temperature of the contactor coil 42energizable to disconnect or connect the power supply from an electricalload, at 104. The method 100 can further include receiving, in thecontroller module 60, a contactor coil operational characteristic, or acontactor coil energizing supply characteristic, at 106.

The method 100 can also include determining, in the controller module60, a total time delay or a contactor time delay 80 for disconnecting orconnecting the power supply 34, by the contactor 32, with the contactortime delay 80 being the summation of a set of delay timings 82, 84, 86based on the electrical signal, the temperature value, and the contactorcoil operational characteristic, at 108. Alternatively, the method 100can include determining, in the control module 60, a total contactortime delay 80 defined by a timing estimation to operably disconnect orconnect the power supply 34 and the electrical load or power supplyoutput 36, based on the coil temperature delay time 82 and the coiloperational characteristic delay time 84, at 108.

Optionally, the method 100 can include determining an initiation time ora contactor initiation time 96 based on the total contactor time delay80 and the AC waveform 92 of the power supply, such that the expirationof the total contactor time delay 80 coincides with a zero-crossingpoint 94 of the AC waveform 92, at 110.

The method 100 can further include initiating, by the controller module60, the disconnecting or connecting of the power supply 34 by thecontactor 32 at an initiation time 96 prior to a zero-crossing point 94in the AC waveform 92, wherein the initiation time 96 anticipates thezero-crossing point 94 based upon the contactor time delay 80, at 112.Alternatively, the method 100 can include initiating, by the controllermodule 60, the disconnecting or connecting of the power supply 34 by thecontactor 32 at the contactor initiation time 96, at 112.

In a non-limiting example, the effective disconnecting or connecting ofthe power supply can coincide with the zero crossing point 94 of the ACwaveform 92. In another non-limiting example, the determining is furtherbased on estimating the contactor time delay 80. In yet another example,the determining is further based on predicting the contactor time delay80. In another example, the determining the contactor time delay 80 isfurther based on the summation of the set of delay timings 82, 84, 86and an error delay time or error correction value 88 defined by adifference between an effective disconnecting or connecting of the powersupply 34 and the zero-crossing point 94 of the AC waveform 92 of atleast one previous contactor 32 disconnection or connection. In yetanother non-limiting example, the error correction value 88 is basedupon a difference in a voltage measured at an effective disconnecting orconnecting of the power supply 34 and a zero value for the voltage. Inanother non-limiting example, the error correction value is furtherbased upon the measured voltage at the effective disconnecting orconnecting, and the AC waveform 92 of the power supply 34. In yetanother non-limiting example, the initiating further includes energizinga solenoid contactor coil 42 with a contactor coil energizing supply 50to operably disconnect or connect the power supply 34. In yet anothernon-limiting example, initiating further includes closing a coil switch48 to provide the contactor coil energizing supply 50 to the solenoidcontactor coil 42. In another example, initiating can further includeenergizing the contactor coil 42 with the contactor coil energizingsupply 50 at the contactor initiation time 96.

The sequence depicted is for illustrative purposes only and is not meantto limit the method 100 in any way as it is understood that the portionsof the method can proceed in a different logical order, additional orintervening portions can be included, or described portions of themethod can be divided into multiple portions, or described portions ofthe method can be omitted without detracting from the described method.

Therefore, it should be appreciated that the contactor assembly 32 asdescribed herein can provide for accurate zero-crossing voltage for aswitch 40. Such accuracy can provide for decreasing contact wear at theswitch 40 itself, leading to increased component lifetime and reducedmaintenance. Furthermore, reduction of contact deposition at zerocurrent and voltage can be achieved. Electromagnetic noise along thepower supply is reduced and can eliminate spikes to a much higher level.Stress on upstream and downstream electrical loads can be reduce, aswell as reducing the occurrence of spikes and surges on said electricalloads. Overall a cleaner power consumption is achieved, which can leadto an overall reduction in power consumption.

The aspects disclosed herein provide a method and apparatus foroperating a contactor assembly. The technical effect is that the abovedescribed aspects enable the disconnecting or connecting of thecontactor after determining a total contactor time and initiating thedisconnection or connecting of the power supply by the contactor at thetotal contactor time or delay such that the effective disconnection orconnection occurs or coincides with a zero-crossing voltage of the inputpower AC waveform, as described herein. The circuit and contactorassembly as described herein can be suitable for different or all typesof power supplies, powered electronics or circuit boards, or anysuitable electrical power distribution system. It should be appreciatedthat the contactor assembly provides for effectively disconnecting orconnecting an AC circuit at a zero-crossing point where the current forthe AC circuit is at or near zero. Utilizing one or more sensors,measurements of the contactor assembly can be provided to a controllermodule. The controller module can determine a set of actual, predicted,or estimated time delay values defining a time between the contactorassembly operably connecting or disconnecting an input with an output,after receiving a command or instruction to do so. Utilizing thedetermined time delay, as described herein, the contactor assembly caninitiate disconnection or connection of the power supply prior to, aheadof, or in anticipation of a zero-crossing point on the AC waveform forthe AC circuit, such that the power supply is effectively disconnectedor connected at or near the zero-crossing point. Therefore, effectivelydisconnecting or connecting the power supply at the zero-crossing pointcan be accurately and consistently achieved. Disconnecting or connectingat the zero-crossing point can reduce contact wear and contactdeposition, which can increase lifetime of the contactor assembly andreduce maintenance. Furthermore, stress on upstream and downstreamelectrical loadings can be reduced, as well as reducing the occurrenceof voltage spikes and surges. Overall power consumption can be cleaner,reducing total power consumption. Noise generated by the contactorassembly is also reduced, and can reduce spikes surges resultant of thereduced noise.

To the extent not already described, the different features andstructures of the various features can be used in combination asdesired. That one feature is not illustrated in all of the aspects ofthe disclosure is not meant to be construed that it cannot be, but isdone for brevity of description. Thus, the various features of thedifferent aspects described herein can be mixed and matched as desiredto form new features or aspects thereof, whether or not the new aspectsor features are expressly described. All combinations or permutations offeatures described herein are covered by this disclosure.

This written description uses examples to detail the aspects describedherein, including the best mode, and to enable any person skilled in theart to practice the aspects described herein, including making and usingany devices or systems and performing any incorporated methods. Thepatentable scope of the aspects described herein are defined by theclaims, and can include other examples that occur to those skilled inthe art. Such other examples are intended to be within the scope of theclaims if they have structural elements that do not differ from theliteral language of the claims, or if they include equivalent structuralelements with insubstantial differences from the literal languages ofthe claims.

What is claimed is:
 1. A method of operating a contactor, the methodcomprising: receiving, in a controller module, at least two operationalcharacteristics of the contactor, with each operational characteristicrepresentative of a delay time; determining, in the controller module, acontactor time delay for at least one of disconnecting or connecting apower supply by the contactor, the contactor time delay being asummation of a set of delay timings based on the delay time of eachoperational characteristic; and initiating, by the controller module,the at least one of disconnecting or connecting of the power supply bythe contactor at an initiation time prior to a zero-crossing voltage ofan alternating current (AC) waveform of the power supply, wherein theinitiation time anticipates the zero-crossing voltage based upon thecontactor time delay.
 2. The method of claim 1, wherein the at least twooperational characteristics of the contactor include at least two of anelectrical signal representative of the AC waveform and of an electricalsignal delay time, a temperature value representative of the temperatureof a contactor coil and of a coil temperature delay time, or a contactorcoil operational characteristic representative of a contactor coiloperational characteristic delay time.
 3. The method of claim 1, whereinan effective disconnecting or connecting of the power supply coincideswith the zero-crossing voltage of the AC waveform.
 4. The method ofclaim 1 wherein the determining is further based on estimating thecontactor time delay.
 5. The method of claim 1 wherein the determiningis further based on predicting the contactor time delay.
 6. The methodof claim 1 wherein the determining the contactor time delay is furtherbased on the summation of the set of delay timings and an errorcorrection value defined by a difference between an effectivedisconnecting or connecting of the power supply along the AC waveformand the zero-crossing voltage of an AC waveform of at least one previouscontactor disconnection or connection.
 7. The method of claim 6 whereinthe error correction value is based upon a difference in a voltagemeasured at an effective disconnecting or connecting of the power supplyand a zero value for the voltage.
 8. The method of claim 7 wherein theerror correction value is further based upon the voltage at theeffective disconnecting or connecting, and the AC waveform of the powersupply.
 9. The method of claim 1 wherein the initiating further includesenergizing a solenoid coil with a coil power supply to operablydisconnect or connect the power supply.
 10. The method of claim 9wherein the initiating further includes closing a coil switch to providethe coil power supply to the solenoid coil.
 11. A method of operating acontactor, the method comprising: receiving, in a controller module, atleast two operational characteristics of the contactor, with eachoperational characteristic representative of a delay time; determining,in the controller module, a total contactor time delay defined by atiming estimation to operably disconnect or connect a power supply andan electrical load, based on the delay time of each operationalcharacteristic; determining a contactor initiation time based on atleast one delay time and an alternating current (AC) waveform of thepower supply, such that an expiration of the total contactor time delaycoincides with a zero-crossing voltage of the AC waveform; andinitiating, by the controller module, a toggling of the power supply bythe contactor at the contactor initiation time.
 12. The method of claim11, wherein the at least two operational characteristics of thecontactor include at least two of an electrical signal representative ofthe AC waveform, a temperature value of a contactor coil energizable todisconnect the power supply from an electrical load, the temperaturevalue representative of the temperature of the contactor coil and of acoil temperature delay time, or a contactor coil operationalcharacteristic representative of a contactor coil operationalcharacteristic delay time.
 13. The method of claim 11 wherein theinitiating further includes energizing the contactor coil with thecontactor coil energizing supply at the contactor initiation time, andwherein an effective toggling of the power supply coincides with thezero-crossing voltage of the AC waveform.
 14. The method of claim 11wherein the determining the contactor time delay is further based on atemperature of a contactor coil, a contactor coil energizing supplycharacteristic, and an error correction value defined by a differencebetween an effective toggling of the power supply by the contactor alongthe AC waveform and the zero-crossing voltage of the AC waveform of atleast one previous contactor disconnection or connection.
 15. The methodof claim 14 wherein the error correction value is based upon adifference in a voltage measured at an effective disconnecting orconnecting of the power supply and a zero value for the voltage.
 16. Acontactor assembly comprising: a contactor switch selectably connectingan input with an output; a contactor coil operably coupled to thecontactor switch and configured to actuate the contactor switch; atleast two sensors configured to measure an operational characteristic ofthe contactor assembly; and a controller module configured to: receiveat least two electrical signals from the at least two sensors, with eachelectrical signal representative of a delay time; determine a contactortime delay as a summation of a set of delay timings based upon the atleast two electrical signals, and initiate at least one of adisconnecting or connecting of the input and the output by the contactorswitch at an initiation time prior to a zero-crossing voltage of analternating current (AC) waveform of a power supply wherein theinitiation time is based upon the contactor time delay.
 17. Thecontactor assembly of claim 16, wherein the at least two sensorscomprise at least two of a contactor coil temperature sensor configuredto measure a temperature of the contactor coil, a contactor coiloperational characteristic sensor configured to measure an operationalcharacteristic of the contactor coil, or an input AC waveform sensorconfigured to measure the AC waveform of the power supply from theinput.
 18. The contactor assembly of claim 17, wherein the contactorcoil temperature sensor is representative of a coil temperature delaytime, the input AC waveform sensor is representative of an electricalsignal delay time, and the contactor coil operational characteristicsensor is representative of an operational characteristic delay time.19. The contactor assembly of claim 16 wherein the controller module isfurther configured to at least one of effectively disconnect oreffectively connect the input and the output when the AC waveform has azero voltage.
 20. The contactor assembly of claim 17, wherein one of theat least two sensors comprise an output voltage sensor configured tomeasure a voltage when the input is at least one of effectivelydisconnected or effectively connected from the output, wherein thecontroller module is configured to receive a fourth electrical signalfrom the output voltage sensor.